The meter mechanism of a conventional electric meter is supported by a meter receptacle having a flanged front aperture. To protect the meter mechanism, a glass blowl with a circular flange is positioned against the meter receptacle so that the glass bowl covers the meter mechanism and the flanges of the glass bowl and the meter receptacle mate. A one-piece locking ring is provided to encircle both flanges in order to hold and clamp the glass bowl to the meter receptacle. The locking ring has a U-shaped cross section which fits over both the glass bowl flange and the receptacle flange as shown in U.S. Pat. Nos. 1,158,953 and 4,413,490. Because the locking ring is a one-piece circular member with a U-shaped cross section, installers have encountered difficulty in spreading the locking ring apart to place it over the glass bowl and meter receptacle flanges.